1. Field of the Invention
This invention relates to automatic test systems for testing electronic components, and in particular, to a participate register for parallel loading of data in pin oriented registers in automatic test equipment.
2. Description of the Prior Art
In automatic test equipment for the testing of integrated circuits, pin electronics interface circuits are coupled to the pins or other nodes of an electronic device being tested. Through the pins, stimuli signals are supplied to the device under test, and output signals from the device under test are detected and measured. Usually, the stimuli signals represent logic states or analog voltages or currents which are desired to be impressed on the pins of the device under test as a parallel pattern, with the resulting output signals checked in parallel.
The interface circuits function as an interface between the computer controlling the test system and the individual pins of the device under test. The interface circuits receive reference voltages and digital data from other circuits in the test system, and then through drivers associated with each interface circuit switch these voltages or data onto desired input pins of the device under test under control of a program stored in the test system computer. Correspondingly, the interface circuits receive voltages or data from output pins of the device under test and supply that data to a comparator circuit which compares the signal received with the proper response stored in the program of the test system computer.
In typical automatic test systems several registers associated with each pin of the device being tested store information concerning attributes to be controlled by those registers. For example, a relay register associated with each pin store information to control the state of relays associated with the pin. Other registers associated with each pin store information concerning reference levels, pin modes of operation, connection of a precision analog measurement unit, etc. In the prior art to supply data to these pin registers, each register associated with each pin was sequentially addressed and the desired data supplied. Because many of the pin registers received identical data, loading this data into registers required long sets of repetitive instructions thereby causing a lengthy set-up period during which the automatic test equipment was unavailable for testing electronic components.